The earliest of these three covers is signed Eric Nitsche. The later two are not signed. The covers are obviously very similar. One of my correspondents told me that Nitsche did not work for Decca after 1954. And Nitsche was too clever to use the same design, I think. Are these unsigned Nitsche covers? Or did someone else at Decca take his design and modify it? Who? If you are my earlier correspondent, please write your theory. Anyone else shed any light?